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Optiplex 980: CPU temp ok, fan speed very high and static
Dear Dell community,
I have recently replaced the CPU in my Optiplex 980 from an i3 530 (that I got for testing the system) to an officially not supported XEON X3470. The microcode to run this CPU has been added in bios revision A16 and I upgraded to the latest A18. The system is running great and the temperatures, as monitored by open hardware monitor, never exceed 35°C in idle and 75°C under load.
However, the CPU fan, starting at its typical low, is quickly ramping up as the machine boots into windows. The GPU fan is increasing ever so slightly, too.
I know the straight answer is that there is a compatibility issue with the motherboard and the CPU. However, I haven't heard of such an issue in the few instances that people utilized XEON processors on the board (and I think it is something worth mentioning).
I did check the wiring of the case temperature sensor and it seems ok, however, I am not sure what a multimeter should read from it (I assume it is a thermistor, so probably 10k or 100k Ohms?), so I cannot confirm whether it really works.
What should a typical reading in open hardware monitor look like for the system? There are not many entries of temperature sensors. For me, only CPU, GPU and HDD temperatures are listed...
Is there a chance that reinstalling Windows 10 would help (while I think that the fancurves are controlled by the bios not the OS, aren't they?)?
Also (while rewriting this post due to the great account creation system on this website) I read that capacitors could be damaged and the Northbridge temperature can trigger the fan, so I will investigate both of those things and update as soon as possible.
Thanks for all the input,
Kamuro
speedstep
8 Wizard
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July 17th, 2018 08:00
There is a bios setting called Fan control override.
I would change the CMOS Battery and set to defaults as a first step.
kamuroNo1
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July 17th, 2018 13:00
Both replacing the CMOS battery and resetting the bios settings to default did not change the behavior :-/
kamuroNo1
3 Posts
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July 18th, 2018 00:00
The capacitors look fine as far as I can see them (there are some hidden under the heatsink mounting bracket) and the northbridge heatsink sits and conducts heat well.
Does anyone have any further ideas?
JasonDab
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April 15th, 2019 03:00
speedstep
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April 15th, 2019 08:00
Thermal paste might be mis applied and or the power supply was not upgraded so he may be overloading the power supply. Either way there is no support for that here.
bradthetechnut
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April 15th, 2019 18:00
Try downloading HWiNFO64.
savvy2
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April 16th, 2019 08:00
the CPU slows down when overheated, or halts at about 90C , Intel inside does that magic
the ROM controls fan speed based on Sensors. running the wrong processor for sure asks for trouble.
windows does not do this, boot a Linux demo disk see the fans still runs fast.
remove the HDD, see the fan still runs too fast, do you see why?
sure wrong CPU, sure, CPU is too many watts for the mobo VRMs sure. but that Xeon you have "hot running"
95watts TPD. the 530 is 73watts.
IDK know if this mobo VRM can do that, did you check that first. ????
first off learn that NO OEM PC maker tests all 100's CPU made on 10,000 sold model PCs. ; IT WILL NEVER HAPPEN. You can , so try more CPU, try them in the same CLASS but faster but do not exceed the TPD of your mobo.
use SHin Etsu Heat sink grease (same as Intel uses on PURPOSE) and only tiny bit, if you lay it on like window caulk the CPU will overheat.. Rice drop sized TIM (thermal inferface material) thin works better the thinner the better and full top coverage after the springs do there magic (flatten out job)
any thing with hype words like Artic or Silver or GOLD , avoid,
and last of all run HWinfo32.exe free from makers site, safe program from makers site, a top class, program.
run that and see if CPU temps hold under heavy load, even run CPU loading program to test it.
The fan speed will be high on any old processor like this, if you load the CPU up to full 95watts burn.
it has no other choice that is it's job if the case fans are dead, then you loose too. the air in the case must cool the CPU via its fan. (no closet PCs allowed in a hot closed closet) I can't see your setup so....
the PC came new with this option
you can not jump CPU Generations and xeon lists are huge, I don't have any compliances lists for Xeons.
https://ark.intel.com/content/www/us/en/ark/products/41315/intel-core-i7-870-processor-8m-cache-2-93-ghz.html
speedstep may know the TPD max on this mobo and would be first. check. as that throws out vast choices.
seems its 95w as the above processor option IS THAT.
if you google others on this tangent.
we see this. Intel Xeon X3430 (shows bench marks) and less than the 870 so why go xeon?
https://www.userbenchmark.com/UserRun/7389507
this old processors all run hot when loaded up, all do. unlike new 7th gen up.
that is what they do, burn power to make speed then, until many DIE shrinks later...
that means cooling will be an issue and for sure done wrong.
You must get the heat off the CPU top to the room and keep the room cool (AC cooled )